Chinon's 55mm f/1.4 — a well-built Japanese M42 fast standard prime.
The Chinon 55mm f/1.4 is a Japanese fast standard prime made in M42 mount by Chinon, a maker of M42 SLRs and lenses. It was the fast normal lens of the Chinon screw-mount range, a typical well-built fast fifty of the era.
This is a manual-focus M42 screw-mount lens with a 55mm focal length and a bright f/1.4 maximum aperture. Focus and aperture are set by hand on the barrel, with an automatic diaphragm. It is a solidly built all-metal fast standard prime. Detailed element figures are not asserted here beyond the verified focal length and aperture, following the accuracy standard.
The slightly-long 55mm with a fast f/1.4 aperture suits portraits, low-light and general work, giving shallow depth of field for subject isolation. Fast standards of this type render smoothly wide open with pleasant out-of-focus areas, firming up stopped down, giving the characterful look many seek from vintage fast fifties.
Used copies are affordable and less common than the mainstream standards. Inspect for haze, fungus and cleaning marks, confirm the aperture blades are clean and oil-free, and check the aperture-ring and focus feel. Verify the M42 mount before purchase. An M42 adapter makes it a characterful fast standard on mirrorless.